Description wikipedia

The mountain elaenia (Elaenia frantzii) is a small passerine bird in subfamily Elaeniinae of family Tyrannidae, the tyrant flycatchers. It is found in Colombia, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama, and Venezuela. The mountain elaenia is 14 to 15 cm (5.5 to 5.9 in) long and weighs about 14 to 24 g (0.49 to 0.85 oz). It is a small to medium size elaenia with a rounded crest. The sexes have the same plumage. Adults of the nominate subspecies have a brownish olive head with lighter cheeks, a thin very pale olive eyering, and a mostly hidden white patch on the crown. Their upperparts are grayish olive. Their wings are mostly dusky with pale olive or olive-yellow edges on the flight feathers. The tips of their wing coverts are yellowish olive and show as two bars on the closed wing. Their tail is grayish brown with pale olive-green feather edges. Their chin, throat, upper breast, and flanks are pale yellowish olive, and their lower breast, belly, and undertail coverts pale straw yellowish. Juveniles are similar to adults but browner above and paler below. Subspecies E. f. ultima has browner (less greenish olive) upperparts and darker, more olivaceous, underparts than the nominate. E. f. pudica is smaller than the nominate and has darker upperparts and paler underparts. E. f. browni is smaller than pudica but with paler, more greenish olive, upperparts. Both sexes of all subspecies have a brown iris, a dark brown maxilla, an orange mandible with a dark brown tip, and dark brown legs and feet.